The present invention relates to a plastic trolley wheel assembly for use in overhead monorail conveyors. Presently, plastic trolly wheels are commonly used in conjunction with metal sleeves, creating a metal to plastic friction bearing. When the trolley wheels have become worn and need to be replaced, the hanger to which the trolley wheel assembly is mounted must also be replaced. For example, the U.S. Pat. No. 2,924,431 to Chadbourne, issued Feb. 9, 1960 discloses a pulley including an integral thermoplastic wheel rotatably mounted on a fixed thermoplastic bearing. The stationary thermoplastic bearing is, in turn, fixedly mounted upon a stainless steel yoke. The narrow end of the yoke is adapted to permit attachment of a hook or another securing device to the yoke.
The U.S. Pat. No. 4,433,627 to Forshee, issued Feb. 28, 1984, discloses a plastic conveyor trolley including a plurality of plastic roller bearings disposed in longitudinally extending arcuate recesses spaced radially apart on the permimeter of a fixed hub section. The plastic roller bearings rotate relative to the fixed hub section when engaged by the body of the plastic trolley wheels.
The U.S. Pat. No. 3,738,477 to Gename, issued Jun. 12, 1973, discloses a packing plant conveyor trolley including a plastic bearing used in conjunction with a trolley wheel. The plastic bearing is fixedly mounted on an axle which terminates at its other end in a hook. The trolley slideably rotates over the fixed plastic bearing.
The present invention incorporates a plastic friction bearing, along with a removably mounted plastic trolley wheel and thus reduces the overall costs and the number of parts to be replaced. Additionally, unlike the prior art constructions, the instant invention teaches a trolley wheel and friction bearing assembly which incorporates the ease of replaceability in an efficient manner.